Prefabricated shelter



FIG. 1 is a front perspective view of a prefabricated shelter showing my new design;

FIG. 2 is a top plan view of a prefabricated shelter showing my new design;

FIG. 3 is a front elevational view, the rear elevational view being the same of a prefabricated shelter showing my new design;

FIG. 4 is a right side elevational view, the left side elevational view being the same of a prefabricated shelter showing my new design; and,

FIG. 5 is a bottom plan view of a prefabricated shelter showing my new design. 

The ornamental design for a prefabricated shelter, as shown and described. 